Washington, DC

The Long Term Control Plan for the District of Columbia Water and Sewer Authority comprises a system of tunnels and diversion sewers for the capture of combined sewer overflows (CSOs) to Rock Creek and the Anacostia and Potomac rivers for treatment at DC Water’s Blue Plains Advanced Wastewater Treatment Plant (BPAWWTP). Shrewsberry is providing construction management services for the construction of Division A – Blue Plains Tunnel. Tasks include field engineering, tunnel inspection and document control.

Work under Division A will extend from BPAWWTP in southwest DC to the Main Pumping Station in southeast DC. This design build project includes a 24,000-foot-long, 26-foot-diameter CSO tunnel constructed in soft ground under and adjacent to the Potomac and Anacostia Rivers. In addition to the tunnel, the project includes a 132-foot-diameter dewatering shaft and a 76-foot-diameter screening shaft at Blue Plains Advanced Wastewater Treatment Plant (BPAWWTP) to serve as main access point for the tunnel construction; a 55-foot-diameter drop shaft at the main pumping station to serve as terminus point; a 50-foot-diameter drop/overflow shaft at Joint Base Anacostia Bolling; and a 55-foot-diameter junction/drop shaft at Poplar Point Pumping Station. The tunnel lining is constructed of bolted/gasketed precast concrete segments.